Ada-Java interface

[Marius Amado Alves <amado.alves@netcabo.pt>]

I'm starting a multilingual (w.r.t. programming language) project. The 
languages include Ada, Java and R. Some central parts are in Java, and 
the other languages are used in satellite parts. At this point we're 
still discussing the means of interfacing between languages. One good 
solution for the Ada-Java interface would be, on the Ada side, to be 
able to import/bind Java classes and packages, and generate JBC. Is 
this viable? Which GNAT version? Any examples? Thanks a lot. To 
illustrate, a Java unit that the Ada part needs to import follows.

package usage;

         // Encapsulates data for a single usage log entry
         class Entry

                 // Usage log entry with given data
                 Entry(
                         User user,
                         Action action,
                         String origin,  // identifies point in GUI that
                                         // triggered this action
                         Date date)

         // Query on the usage log
         class Query

                 // creates new query
                 Query()

                 // list entries of given users
                 // set null for all users (default)
                 setUsers(Users[])

                 // list entries with given actions
                 // set null for all actions (default)
                 setActions(Action[])

                 // return only entries after given date
                 // set null to begin with first recorded entry (default)
                 setBeginDate(Date begin)

                 // return only entries before given date
                 // set null to end with last recorded entry (default)
                 setEndDate(Date end)

                 // execute query with current restrictions
                 usage.execute()

                 // returns iterator with each Entry matching this query
                 Iterator iterator();